The suspended self-propelled trolley system based on PLC control system is simple, easy to use, high reliability, and has greater flexibility and reliability.
It is widely used in industrial material conveying line. The distributed control system of self-propelled car is analyzed, and the control of single self-propelled car is decomposed. Suspension self-propelled car system has been widely used in automobile manufacturing, construction machinery, intelligent warehousing and other industries. This not only facilitates the transmission and inspection of materials, but also brings more economic benefits to manufacturing enterprises. This paper studies and designs the automatic control of the electrophoretic painting suspension self-propelled trolley conveyor line system of an automobile production company in Henan Province. It realizes the control and monitoring of the conveyor system with the cooperation of S7-300, S7-200 and touch screen of Siemens. This paper briefly introduces its automatic control system. Self-propelled trolley is an electric trolley running on a specific air track, which can form a load-bearing, fully automatic material handling system.
Its composition is composed of steel structure, suspension device, track, translation turnout, vertical lifting device, trolley, electric hoist, hanger, safety slip contact wire, collector, sensor and control system. As the system integrates optical, mechanical, thermostatic element electrical and computer technologies, it is a key equipment for highly automated new material transportation. At present, there are many control modes for the self-propelled trolley conveyor line. The distributed control mode is adopted in this system. The whole self-propelled trolley line is a closed ring, which is formed by I-shaped steel track. Sliding contact wire is installed on the side of I-shaped steel track to provide power supply and control signal for the self-propelled trolley. The whole loop line is divided into several stations, each station is equipped with a ground button station (manual control of bicycles). The number of self-propelled cars on the power line sliding contact line is determined by the production line rhythm and can be increased or decreased by itself.
The whole line is a distributed control mode. A single car can stop at the station section alone.
It can also stop at the same time in the storage section. The main control components of the system are installed in the control cabinet of the control room. Siemens S7-300 CPU is connected with the slave station through PROFIBUS field bus. The control signal is transmitted from the station to the control cabinet of each car by sliding line. The control cabinet of each car has a set of S7-200 control system to control the start-stop, advance, hoist lifting and other actions of the car. The project consists of 26 workstations, each of which is set up according to the requirements of the painting production line.
Eight sliding lines are used to control the project. Each self-propelled car is equipped with two collectors. (1) The upper four sliding lines provide power for the car system; (2) the lower four sliding lines provide control signal transmission for the car system, and the sliding lines of the control signal are disconnected into two sections between each station.
Siemens S7-200 series is used for the control of the self-propelled car.
Its CPU adopts CPU224/AC/DC/relay (6ES7 214-1BD23-OXB8). As shown in the control chart of the trolley sliding line (1) Signal 1, Signal 2 and Signal 3 are combined signals. The lifting control function of the hoist is realized by different combinations of the three signals. (2) The walking function of the self-propelled car is controlled by the forward signal (3) the upper signal controls the hoist to rise to its position (4) the encoder signal controls the descending distance of the hoist, and provides the data basis for the synchronous control of the hoist.
(5) The fault signal reflects the running state of the car, and it can be used to reflect the running state of the car on the main control cabinet to eliminate the car fault in time. At present, the self-propelled trolley transmission line has the advantages of simple structure, convenient operation, strong reliability and fast transmission speed. It can save a lot of labor. At present, the self-propelled trolley conveyor line control system has been used on the electrophoresis line and material transfer line of many domestic manufacturers. It has been proved that the system has high reliability and is easy to modify. Especially, it is fast and convenient to add functions and modify actions. Although the use and structure of each manufacturer are different, the specific ideas are interlinked.